[47] Chondroid Chordoma: A Chordoma Subtype with Worse Prognosis

Darcy A Kerr, Vikram Deshpande, Pawel Kurzawa, GP Nielsen. Massachusetts General Hospital, Boston, MA; Greater Poland Cancer Centre, Poznan, Poland

Background: Chordoma is a rare tumor that accounts for 1-4% of primary malignant bone tumors and usually arises in the axial skeleton. Chondroid chordomas occur almost exclusively at the base of the skull and demonstrate morphologic features of chordoma with chondroid areas mimicking cartilaginous neoplasms. Some sources indicate a better prognosis for this subtype of chordoma, but the finding is not universal and studies have included relatively small numbers of chondroid chordomas for assessment.
Design: We aimed to compare the prognosis of chondroid and conventional chordomas of the clival region, the most common location for chondroid chordomas. Our pathology database contained 273 patients with chondroid chordomas from 1990 to the present. 109 of these patients had both clival tumors and available clinical follow up. We compared this cohort to a group of 32 clival conventional chordomas chosen on availability of clinical follow up. Clinicopathologic features and prognosis were compared using logrank tests and Kaplan-Meier curves.
Results: Chondroid chordoma patients were 44% female and 37.2 years on average; patients with conventional chordomas were 47% female and averaged 37.4 years. Differences in age and gender were non-significant (p = 0.49 and 0.46, respectively). Patients with chondroid chordomas had a poorer overall mean survival than those with conventional chordomas (187.4 vs. 207.7 months, p = 0.02) as shown in Figure 1. Additionally patients with chondroid chordomas had a shorter disease-free mean survival than those with conventional chordomas (57.4 vs. 127.4 months, p = 0.001).


Conclusions: Chondroid chordomas of the clivus appear to exhibit a poorer prognosis than clival conventional chordomas. Our results are in contrast to historical reports of chondroid chordomas with a better than or similar prognosis to conventional types. To our knowledge this study represents the largest cohort of chondroid chordomas analyzed. Additional studies are underway to assess for possible contributing factors and increase the size of the comparison cohort. While these findings should be confirmed with further research, our experience indicates that chondroid chordomas may represent a distinct biological subset of chordomas with a more aggressive behavior.
Category: Bone & Soft Tissue

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 7, Tuesday Afternoon

 

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